Magnetic recording medium and manufacturing process thereof
AssigneeFuji Electric Co., Ltd.
InventorsYoshiharu Kashiwakura, Yoshihumi Ajishi, Tetsu Ikegami
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Abstract
A magnetic recording medium has a non-magnetic ground layer, a non-magnetic recording layer, a protecting layer formed sequentially on a non-magnetic substrate, one on top of another. A double-layered non-magnetic ground layer consists of a pure chromium layer, positioned closer to a substrate, and a chromium-molybdenum-tungsten ternary alloy layer, positioned closer to a magnetic recording layer. This provides the non-magnetic recording layer formed on such a ground layer with cobalt alloy grains having uniform dimensions. The resulting magnetic recording medium has an excellent SNR.
Claims5
A multi-layered magnetic recording medium having at least three thin films comprising:
- a non-magnetic substrate;
- a non-magnetic ground layer;
- said non-magnetic ground layer having a total thickness of 20 nm or less;
- a magnetic recording layer;
- a protecting layer;
- said non-magnetic ground layer, magnetic recording layer and protecting layer being formed sequentially on said non-magnetic substrate, one on top of another;
- said non-magnetic ground layer being double-layered, including a first non-magnetic metal layer and a second non-magnetic metal layer, said first non-magnetic metal layer having a composition different from said second non-magnetic metal layer;
- and
- said first non-magnetic metal layer, being a pure chromium layer, is positioned closer to said non-magnetic substrate;
- and
- said first non-magnetic metal layer having a thickness from 20% to 80% of a total thickness of said non-magnetic ground layer;
- and
- said second non-magnetic metal layer, being a chromium-molybdenum-tungsten ternary alloy layer, is positioned closer to said magnetic recording layer.
A manufacturing process for a magnetic recording medium comprising the steps of:
- (a) forming at least a pure chromium ground layer, a chromium-molybdenum-tungsten ternary chromium alloy ground layer, and a magnetic recording layer sequentially on a non-magnetic substrate, one on top of another with a sputtering technique, wherein said pure chromium ground layer has a thickness from 20% to 80% of a total thickness of said pure chromium ground layer and said chromium-molybdenum-tungsten ternary chromium alloy ground layer, and wherein said total thickness is 20 nm or less;
- and
- (b) forming a protecting layer with one of a sputtering technique and a CVD technique.
Dependencies are inferred from the claim text.